Device for lifting the abdominal wall for laparoscopy

ABSTRACT

Disclosed is a device for lifting the abdominal wall for laparoscopy, whereby the device can be inserted into the abdominal cavity through an opening in the abdominal wall, having an instrument shaft, which is provided at its distal end region with at least one, preferably two limbs disposed parallel to the axis of the instrument shaft and the can be folded open laterally to the shaft axis. The invention is distinguished by the limbs being joined to the instrument shaft via a folding mechanism, which rotates the limbs at an angle ranging up to 180°.

TECHNICAL FIELD

The present invention relates to a device for lifting the abdominal wallfor laparoscopy, whereby this device can be at least partially insertedinto the abdomen through an opening in the abdominal wall.

STATE OF THE ART

Generic type devices possess an instrument shaft which is provided atits distal end region with at least one, preferably two parallel limbsdisposed parallel to the axis of the instrument shaft. The limbs can befolded open laterally to the axis of the shaft.

Devices of the above class, employed in the field of endoscopic surgery,for laparoscopy respectively laparoscopic treatment, are also knownunder the term “elevation instruments” Instruments of this type areinserted into the abdominal cavity through a narrow opening and, byfolding the holding supports open laterally, provide a wide fan supportin order to be able to lift as large as possible an area of theabdominal wall. In this way, the surgical area required inside theabdominal lumen is created for subsequent laparoscopy as well asendoscope-supported surgery.

The elevation instruments used for widening the abdominal cavity,should, on the one hand, have a small as possible cross section so thatthe opening in the abdominal wall through which the instrument isinserted inside the abdomen can be maintained as small as possible and,on the other hand, however the carrier arms or hereinafter called limbs,which can be folded open laterally to the side of the instrument offer awide as possible fan support for the abdominal wall.

The following demands are made on the rotating respectively foldingmechanism, by which the limbs are folded away from the axis of theinstrument:

The folding open and shut procedure should occur inside the abdominalcavity in a reliable and dosed manner. The whole carrier mechanismshould be provided with sufficient stability for bearing the weight ofthe abdominal wall and at the same time require as little space aspossible. Furthermore, safety devices should be provided in order to beable to remove the elevation instrument from the abdomen again if thefolding mechanism fails.

The article by Albert K. Chin et al., “Gasless Laparoscopy Using aPlanar Lifting Technique”, in the Journal of the American College ofSurgeons, April 19194, vol. 178, pp. 401-403, describes a generic typedevice for mechanically lifting the abdominal wall which permitscarrying out laparoscopic surgery without continuous gas insufflationinto the abdominal cavity. The gas bubble inside the abdominal cavitycreated by the insufflation of, preferably, carbon dioxide can lead toreducing the breathing capacity and diminished vein return flow due tothe artificial maintenance of a relatively high pressure. Generic typeelevation instruments are utilized in order to avoid this and otherdrawbacks for the patient.

The generic type device described in the aforementioned article providesfor a handling shaft at the distal end region of which an expandingdevice, which assumes a closed position for insertion into the abdominalcavity, is attached at a right angle to the axis of the shaft so thatthe expanding shaft can be brought into the abdominal cavity throughvery narrow abdominal openings. Due to an operating mechanism attachedto the handling shaft, the folding mechanism can be folded openscissorlike inside the abdominal cavity, whereby two limbs provided in aV position lift the abdominal wall intracorporally by appropriatelifting of the instrument.

Removal of the device is not possible until the limbs set in the Vposition have been returned to a parallel position by the correspondingoperating mechanism. However, if pieces of tissue are present betweenthe limbs, these may be bruised or irreversibly damaged when the limbsare closed again. Moreover, in such an event, complete closing of thetwo limbs is impossible, thereby considerably impeding gentle removal ofthe instrument through the small opening in the abdomen.

Furthermore, generic type devices are known which provide limbs that canbe folded open parallel to the axis of the shaft of the instrument,which following insertion into the abdominal cavity through very narrowabdominal openings fold open inside the abdominal cavity like themechanism of an umbrella and with appropriate lifting of the instrumentlift the abdominal wall intracorporally from below in the direction ofthe movement of the instrument. With these type of folding mechanisms,which preferably occupy a region of rotation between the parallelposition to the axis of the shaft and an orthogonal position to the axisof the shaft, the problem arises that pieces of tissue in the abdominalcavity can considerably impede closing the limbs again. However,incomplete closing of the individual limbs leads to a kind of catching,the removal of which through the small abdominal opening inevitablydamages the tissue surrounding the abdominal opening.

DESCRIPTION OF THE INVENTION

The object of the present invention is to improve a device for liftingthe abdominal wall for laparoscopy according to the generic part ofclaim 1 in such a manner that the aforedescribed risk of incompleteclosing of the instrument limbs expanded for lifting the abdominal walldue to, for example catching or pinching pieces of tissue, is largelyruled out. For this purpose, a folding mechanism should be used forfolding the expanding limbs open with as little use of space as possiblein order to avoid intracorporal tissue irritation. Nonetheless, theinstrument should be easy to operate without requiring major force.

A solution to the object is set forth. Further features whichadvantageously improve the concept of the solution are disclosed.

An element of the present invention is to improve a device for liftingthe abdominal wall for laparoscopy in such a manner that the limbs arejoined with the shaft of the instrument via a folding mechanism whichrotates the limbs at an angle range up to 180°.

In this manner, for removal of the instrument out of the abdominalcavity, the limbs folded open for lifting, preferably in an orthogonalposition to the shaft of the instrument, can be folded either to theproximal side of the instrument parallel to the axis of the shaft of theinstrument or, if the limbs are prevented from fitting completely closeto the axis of the instrument by caught pieces of tissue, to fold in theopposite direction, i.e. toward the distal side, until the limbs fitclosely parallel to the axis of the shaft of the instrument in order tobe able to remove the instrument in this position easily from theabdominal cavity through the abdominal opening.

BRIEF DESCRIPTION OF THE DRAWING

The invented 180° folding mechanism is made more apparent by way ofexample using a preferred embodiment with reference to the accompanyingdrawings, showing in:

FIG. 1 a basic sketch of an invented elevation instrument for use in apatient's abdominal cavity,

FIG. 2A is a diagrammatic view of an invented folding mechanism duringinsertion,

FIG. 2B is a diagrammatic view of an invented folding machine withpartially unfolded limbs,

FIG. 2C is a view similar to a view if FIG. 2B but illustrating fullyunfolded limbs,

FIG. 3 a diagram of the distal end region of the shaft of theinstrument,

FIG. 4 a top view of a shaft having an integrated guide track, and

FIG. 5 a representation of the force conditions in the control curve.

DESCRIPTION OF A PREFERRED EMBODIMENT

FIG. 1 is a diagrammatic top view of a patient P, whose legs B anddiaphragm Z are shown. The elevation instrument is inserted inside thebody through a corporal opening N. The elevation instrument is providedwith an instrument shaft 1 and two limbs 2 and 3 which can be foldedopen laterally to the axis A of instrument shaft 1. An element of thepresent invention is that the limbs 2 and 3 can be rotated at an anglerange of 0°≦α≦180°.

The positions α=0° correspond to the limb position for insertion of theinstrument through the abdominal opening N. If the limbs can no longerbe folded back to the initial position, be it due to caught pieces oftissue or mechanical failure, both limbs can be folded to the 180°position. In this manner, the ability to remove the instrument againthrough the abdominal opening N is given in any event.

The details of FIGS. 2a to 2 c show the basic principle of the foldingmechanism. In side views of the distal end region of the inventeddevice, on instrument shaft 1 in the representation according to FIG.2a, a limb 2 is shown in parallel position to the axis of the shaft. Inthis arrangement, the instrument shaft is brought inside the abdomenthrough a abdominal opening, not depicted in the figure. Fundamentally,the foldable limbs 2 and 3 each are provided with a control curve 4(FIG. 4) which is integrated in a lateral end region of each limb.Control curve 4 may be designed as a groove or as a slit runningcompletely through the material of the limb.

In addition to control curve 4, each limb is provided with a rotatable,moveable joining means 5. Joining means 5 projects through a guide track6 designed as a slit, which is integrated in the distal region ofinstrument shaft 1 and joins in this manner the two limbs 2 and 3. Inaddition to guide track 6, the distal region of instrument shaft 1 isprovided per limb side with a control pin 7 which is fixedly attached tothe instrument shaft and which projects through the control curve 4 ofthe respective limb.

With the aid of the resulting folding mechanism, the limbs can bebrought from the parallel position according to FIG. 2a into theorthogonal position according to FIG. 2b by moving the joining meansproximally along the guide track 6.

Due to the axial movement of joining means 5 along guide track 6, eachlimb experiences a torque as a result of control pin 7 engaging in thecontrol curve, which torque rotates the limbs about the joining means 51which is simultaneously also the rotating center of the limbs, andtherewith each limb also experiences a tilting indicated by the curvedarrows. If joining means 5 is located at the end of guide track 6 facingthe proximal side, both limbs are aligned parallel to the axis of theinstrument at the distal side (for this see FIG. 2c).

The kinematic triggering of joining means 5 for axial movement occursvia an operating element, not depicted in FIG. 2, which may be executedin the form of a connecting rod. Depending on the position of the limbs,they can be stopped in their position by means of the connecting rod.

FIG. 3 shows a diagrammatic view of an advantageous embodiment of thedistal end region of an instrument shaft 1. The control pin, whichengages in the control curve of the respective limb, is fixedly disposedlaterally beside guide track 6. The longitudinally moveable joiningmeans 5, which projects through guide track 6 of the instrument shaftand joins kinematically both limbs, can be stopped in each position bymeans of a not depicted operating element.

FIG. 4 shows an advantageously designed limb 2 which is provided with across which indicates the point of penetration of joining means 5. Theparticularly advantageously designed control curve is designed in such amanner that it is integrated completely in the limb region and does notintersect itself.

The control curve form shown in FIG. 4 permits, in particular, thatuniform moving of the joining means leads to a uniform movement of thelimbs about their point of rotation.

The folding movement of the limbs is generated by a torque which occursby guiding the control pin inside the control curve. By means of thesliding movement of the control pin inside the control curve, the latterexercises a force FS on the external contour of the curved groove. Thisis shown in FIG. 5. Force conditions of a self-acting incline set in.Thus force FS divides into the components descending incline force FHand normal force FN. Normal force FN is responsible for the movement ofthe limbs. The larger their share in the force plan is, the more forceis at disposal for generating the moment MS. However, with increasingnormal force, the surface pressure between the pin and the contour ofthe control curve also increases and therefore also the work consumed byfriction required for the movement.

In order for the control pin to be able to run easily through the curvecontour, the share of the component descending incline force FH isselected not too small. The angle β should therefore not be larger than65° at any point of the curve. In this manner it is ensured that atleast ¼ of the required force occurs as descending incline force.

What is claimed is:
 1. A device for lifting the abdominal wall forlaparoscopy, whereby said device can be inserted into the abdominalcavity through an opening in the abdominal wall, said device having aninstrument shaft, which is provided at its distal end region with atleast one limb disposed parallel to an axis of said instrument shaft,said at least one limb can be folded open laterally to said shaft axis,said device characterized by the fact that said at least one limb arejoined to said instrument shaft via a folding mechanism, which rotatessaid at least one limb at an angle ranging up to 180°.
 2. A deviceaccording to claim 1, characterized by the fact that said at least onelimb has a flattened rod shape and a width corresponding maximally tothat of a distal width of said instrument shaft.
 3. A device accordingto claim 1, characterized by the fact that an operating element isprovided which actuates said folding mechanism from the proximal side ofsaid instrument shaft.
 4. A device according to claim 1, characterizedby the fact that said at least one limb can be stopped at least in oneposition perpendicular to said axis of said instrument shaft.
 5. Adevice according to claim 1, characterized by the fact that two limbsdisposed on an instrument shaft are fixedly joined to each other in arotatable manner via a pin-like joining means which at the same timeforms a common axis of rotation of said limbs.
 6. A device for liftingthe abdominal wall for laparoscopy, whereby said device can be insertedinto the abdominal cavity through an opening in the abdominal wall, saiddevice having an instrument shaft, which is provided at its distal endregion with at least one limb disposed parallel to an axis of saidinstrument shaft, said at least one limb can be folded open laterally tosaid shaft axis, said device characterized by the fact that saidinstrument shaft is provided in its distal end region with a guide trackrunning parallel to said axis, said at least one limb is joined to saidinstrument shaft via a folding mechanism, which rotates said limbs at anangle up to
 180. 7. A device according to claim 6, characterized by thefact that said guide track is a groove or a guide slit runningcompletely through said instrument shaft.
 8. A device according to claim6, characterized by the fact that said at least one limb is provided inone of its lateral end regions with a control curve and a pin-likejoining means which fixedly joins said at least one limb in a rotatablemanner about said joining means and in a moveable manner along saidguide track of said instrument shaft.
 9. A device according to one ofthe claim 8, characterized by the fact that said control curve isdesigned as a slit.
 10. A device according to claim 8, characterized bythe fact that by means of moving said joining means along said guidetrack of said instrument shaft, said folding mechanism effects a lateralexcursion of said at least one limbs by means of the resulting relativemovement of said control pin inside said control curve.
 11. A deviceaccording to claim 10, characterized by the fact that an operatingelement is provided which actuates said folding mechanism from theproximal side of said instrument shaft.
 12. A device according to claim11, characterized by the fact that said operating element engagesactively with said joining means.
 13. A device according to claim 8characterized by the fact that an operating element engages activelywith said joining means.
 14. A device for lifting the abdominal wall forlaparscopy, whereby said device can be inserted into the abdominalcavity through an opening in the abdominal wall, said device having aninstrument shaft, which is provided at its distal end region with atleast one limb disposed parallel to an axis of said instrument shaft,said at least one limb can be folded open laterally to said shaft axis,said device characterized by the fact that said at least one limb isjoined to said instrument shaft via a folding mechanism including aguide track running parallel to said axis of the instrument shaft, whichrotates said at least one limb at an angle.
 15. A device according toclaim 14, characterized by the fact that said at least one limb isprovided in one of its lateral end regions with a control curve and apin-like joining means which fixedly joins said at least one limb in arotatable manner about said joining means and in a moveable manner alongsaid guide track of said instrument shaft.
 16. A device according toclaim 15, characterized by the fact that said control curve engages witha control pin fixedly attached on said instrument shaft.
 17. A devicefor lifting the abdominal wall for laparoscopy, whereby said device canbe inserted into the abdominal cavity through an opening in theabdominal wall, said device having an instrument shaft, which isprovided at its distal end region with at least one limb disposedparallel to an axis of said instrument shaft, said at least one limb canbe folded open laterally to said shaft axis, said device characterizedby the fact that said at least one limb is joined to said instrumentshaft via a folding mechanism, said at least one limb is provided in oneof its lateral end regions with a control curve and a pin-like joiningmeans which fixedly joins at least one limb in a rotatable manner aboutsaid joining means and in a movable manner along a guide track of saidinstrument shaft.
 18. A device according to claim 17, characterized bythe fact that said control curve engages with a control pin fixedlyattached on said instrument shaft.
 19. A device according to claim 18,characterized by the fact that two limbs disposed on an instrument shaftare fixedly joined to each other in a rotatable manner via a pin-likejoining means which at the same time forms a common axis of rotation ofsaid limbs.
 20. A device for lifting the abdominal wall for laparoscopy,comprising: an elongated shaft extending along a longitudinal axis andhaving a distal end; a pair of limbs mounted on the distal end of theelongated shaft; a folding mechanism on said elongated shaft andconnected to the pair of limbs to rotate them in opposite directions ata 180 angle between first and second positions, wherein the limbs extendparallel to the longitudinal axis.